GHOST Split Idol Theory

The artwork is reminiscent to that of religious pieces in that we have a halo with the typical lines representing rays of light, followed by the character in robes. The wings are also rather angelic, obviously. It's clear that this person is looked up to.
The split comes when we have the tainted, tar-like substance covering their other half to express that the character in the artwork is not holy, and definitely not a saint. Tar is, typically, unpleasant, and it appears as though it's covering them in a way they are not happy with-- yet they still don't pay it any mind.

The mechanical parts are, as prior mentioned, similar to the story of Serial Contraption of Malice. The premise of that song is that there is a machine who views themselves as human, and knows there's something different between them and normal people. Unsure of this split, they proceed to dissect humans in order to figure out what's different.
Machines are, themselves, non-human; they are simple in that they can take an input and give an output, and mechanical parts tend to control one's actions. In the song Serial Contraption of Malice, additionally, the machine yearns to become human, or "normal."
It's probably not unsafe to say that the figure in the artwork feels as if they are mechanical in their actions, and feels inhuman, or that they have something else that separates them from others.

On top of this, there are, clearly, human parts, so there's always the possibility that they also feel as though they are controlled by machines.

That being said, we now have the potential meaning of the song:
The "idol" in the artwork is praised and viewed in a saint-like manner, yet they have a tarnished, flawed side to them which they dislike and have to deal with. They also feel somewhere between machine-like and inhuman.

Misc other possibilities:
- Devoid of color. Something uninteresting/dull. Perhaps that's only to sell the monochrome half-and-half of "saint-like vs deeply flawed" that the artwork conveys.
- They seem to be held up/assisted in standing by the machine, seen on the character's right side (left side of the artwork). Couple ideas what this means if anything, but nothing conclusive.
- Three pairs of wings. That's a lotta wings. Not sure what it could mean yet, but it's probably just an aesthetic choice. It's super aesthetic my guy.
- Their arms don't exist. I'm pretty sure this's something important, but I'm not sure what it means.
- Their eyes are full-black without pupils or sclera or an iris or anything, much like a Tiefling's from Dungeons and Dragons. This might mean something, but it's probably to push the feeling of something emotionless, lifeless, or inhuman. Leaning towards the latter two rather than the first.